Package org.orekit.models.earth.weather

Class GlobalPressureTemperature2Model

  • All Implemented Interfaces:
    WeatherModel
    public class GlobalPressureTemperature2Model
extends Object
implements WeatherModel
    The Global Pressure and Temperature 2 (GPT2) model. This model is an empirical model that provides the temperature, the pressure and the water vapor pressure of a site depending its latitude and longitude. This model also provides the ah and aw coefficients used for the Vienna 1 model.

    The requisite coefficients for the computation of the weather parameters are provided by the Department of Geodesy and Geoinformation of the Vienna University. They are based on an external grid file like "gpt2_1.grd" (1° x 1°) or "gpt2_5.grd" (5° x 5°) available at: link

    A bilinear interpolation is performed in order to obtained the correct values of the weather parameters.

    The format is always the same, with and example shown below for the pressure and the temperature.

    Example: 

     %  lat    lon   p:a0    A1   B1   A2   B2  T:a0    A1   B1   A2   B2
   87.5    2.5 101421    21  409 -217 -122 259.2 -13.2 -6.1  2.6  0.3
   87.5    7.5 101416    21  411 -213 -120 259.3 -13.1 -6.1  2.6  0.3
   87.5   12.5 101411    22  413 -209 -118 259.3 -13.1 -6.1  2.6  0.3
   87.5   17.5 101407    23  415 -205 -116 259.4 -13.0 -6.1  2.6  0.3
   ...
    Author:
    Bryan Cazabonne
    See Also:
    "K. Lagler, M. Schindelegger, J. Böhm, H. Krasna, T. Nilsson (2013), GPT2: empirical slant delay model for radio space geodetic techniques. Geophys Res Lett 40(6):1069–1073. doi:10.1002/grl.50288"

    • Field Detail

      • DEFAULT_SUPPORTED_NAMES

        public static final String DEFAULT_SUPPORTED_NAMES
        Default supported files name pattern.
        See Also:
        Constant Field Values

    • Constructor Detail

      • GlobalPressureTemperature2Model

        public GlobalPressureTemperature2Model​(String supportedNames,
                                       double latitude,
                                       double longitude,
                                       Geoid geoid,
                                       DataProvidersManager dataProvidersManager,
                                       TimeScale utc)
        Constructor with supported names and source of GPT2 auxiliary data given by user.
        Parameters:
        supportedNames - supported names
        latitude - geodetic latitude of the station, in radians
        longitude - longitude geodetic longitude of the station, in radians
        geoid - level surface of the gravity potential of a body
        dataProvidersManager - provides access to auxiliary data.
        utc - UTC time scale.
        Since:
        10.1

    • Method Detail

      • getA

        public double[] getA()
        Returns the a coefficients array.
        • double[0] = ah
        • double[1] = aw
        Returns:
        the a coefficients array

      • getTemperature

        public double getTemperature()
        Returns the temperature at the station [K].
        Returns:
        the temperature at the station [K]

      • getPressure

        public double getPressure()
        Returns the pressure at the station [hPa].
        Returns:
        the pressure at the station [hPa]

      • getWaterVaporPressure

        public double getWaterVaporPressure()
        Returns the water vapor pressure at the station [hPa].
        Returns:
        the water vapor pressure at the station [hPa]

      • weatherParameters

        public void weatherParameters​(double stationHeight,
                              AbsoluteDate currentDate)
        Description copied from interface: WeatherModel
        Calculates the weather parameters of the model. In order to obtain the correct values of the parameters this method has to be call just after the construction of the model.
        Specified by:
        weatherParameters in interface WeatherModel
        Parameters:
        stationHeight - the height of the station in m
        currentDate - current date